Sound synchronizing equipment



May 13, 1941. F. c. WALLACE 2,241,495

souun SYNCHRONIZING EQUIPMENT Filed Dec. 14, 1938 2 Sheets-Sheet l INVENTOR Fred C. WaZZace W MVM y 1941- F. c. WALLACE 2,241,496

SOUND SYNCHRONIZING EQUIPMENT Filed Dec. 14,. 1938 2 Sheets-Sheet 2 INVENTOR Fred C. Wallace Patented May 13, 1941 UNITED STATES PATENT OFFICE {SOUND SYNCHRONIZING EQUIPMENT Fred C. Wallace, Pittsburgh, Pas, assignor to Gardner Displays Company, Pittsburgh, Pa., a corporation of Pennsylvania V Application December 14, 1938, Serial No. 245,663 3 Claims. totem- This invention relates to sound synchronizing equipment and is particularly useful for synchronizing the sounds emitted by sound producing means and the operation of associated electrical or mechanical equipment so that the equipment will operate at a time or times having definite relation to a narrative, music or other tones reproduced, for example, from a phonograph record.

My apparatus is characterized by its simplicity and improved results and particularly by its ability to continually synchronize sound effects and the operation of equipment no matter how often a series of sound effects and equipment operations are repeated. One of the objects of the invention. is to provide means to control the operation of mechanical or electrical equipment in conjunction with the reproduction of a predetermined sound sequence, the operation of the equipment being controlled in synchronization with the sound production. Such equipment is especially well adapted for operating mechanical or electrical displays such as may be arranged in exhibitions or displays in conjunction with a loud speaker which reproduces a sound ferred embodiment of my invention.

sequence, which may comprise an oral descripand the word robot will be hereafter used to designate such equipment, although it is to be understood that such equipment may embrace other equipment, such as, for example, an animated display.

Another object is to provide a record adapted for use in automatic lecturing and. demonstrating equipment, such as in robot phonographs, whereby sounds may be reproduced from a sound track or record, operated in conjunction with electrical circuits or equipment which also controls the operation of the robot.

A further object is to provide means for insuring that the record or sound producing mechanism will always be operated in a cycle timed so as to synchronize with the movement of the robot and this synchronization continues no matter how often the record is repeated. Means are provided for setting the mechanism to a predetermined starting position just before the beginning of the cycle of operation. The desired electrical circuits are controlled in perfect synchronization with the narrative.

The equipment once synchronized remains so no matter how often the record is repeated as the apparatus is so devised that there. is a slight delay between each playing ofthe record, and during this delay all parts of the apparatus are automatically reset and placed in absolute synchronization. Means are provided to insure that When a record is used the needle on the tone armwill always start in the same place in the sound groove and at the same instant of time relative to the robot movements.

These results are obtained by connecting a repeating phonograph mechanism with contact making and breaking means so that certain desired electrical circuits are controlled at definite intervals. In setting up a mechanism for use with a particular record, the circuits are arranged so as to be operated at the desired times and inthe proper sequence, for electrically performing the desired results.

In the accompanying drawings I have shown for purposes of illustration only the present pre In the drawings:

Figure 1 is a diagrammatic view of the apparatus showing the record repeating mechanism and synchronized'electrical circuits and a robot;

Figure 2 is a plan View of a record disc and associated tone arm;

Figure 3 is a view in elevation of the disc, turntable, tone arm and certain associated equipment; and

Figure 4 is a View in elevation of the timing disc assembly but to a different scale.

The apparatus in general consists of record playing and repeating mechanism and a timing circuit through which electrical connections can be made of a desired duration and at predetermined intervals of time to control the operation and movement of the robot, or other electrically operated devices. I

The record repeating mechanism consists of a phonograph and means for automatically repeating the playing of a record as often as may be required. The timing circuit consists of a timing disc assembly which is connected to the drive 'mechanism of the phonograph turntable so that the timing discs which are included in the timing disc assembly are always in synchronism withthe phonograph record. Each of the timing discs controls an electrical circuit which directly or indirectly controls apparatus which accomplishes the desired mechanical and electrical results.

In Figure 1 there is shown a phonograph of the usual type which has a movable stylus arm or "pickup device 2 with conductors 3 leading to a suitable amplifier or loud speaker 4, conveniently located in the robot R. The sound record 5, which is here shown as a flat disc, although other forms of sound producing mechanism may be used, has a sound groove 6 which terminates toward the center of the record in an open spiral l. The record 5 is supported on the turntable 8 which has a centering pin 9 and an offset positioning pin Ill. Th pins 9 and I cooperate with appropriate holes in the record so that the record, when placed on the turntable 8, is in a definite angular position with respect thereto and always remains in that position. The turntable is driven by a supporting shaft l l which is rotated at'a desired speed by a motor l2 through an appropriate gear connecperiod of time is controlled by the operation of a starting and reset switch 24. This switch is operated by the movement of a timing disc assembly generally denoted by the numeral 25 which will be described later. When the starting switch 24 is closed, the motor 23 operates to turn the cam 22 counter-clockwise and the pusher arm 2| is moved to the left to push the stylus arm to its starting position on the record 5. It is understood that the stylus arm is or has been lifted clear of the record before the pusher arm 2| moves the stylus arm to its starting position. An abutment 26 on the pusher arm 2| allows a limit switch 21 to close and. current will then be tion |3. Th motor I2 is connected to a power supply (not shown). The supply of electric energy to the whole apparatus is controlled by a switch M. The tone arm 2 is of a type common:

I prefer to use records which have the sound track 6 arranged on a spiral from the inside to the outside of the record. Of course the sound track may be arranged from, the outside to the inside if desired. The sound track in my preferred form commences on the inside of the record in a spiral groove portion 1 of greater pitch than the sound track 6 and is an extension thereof. Just prior to sound emission the stylus is in a position toward the center of the record and'moves outwardly during the playing of the record to a position adjacent the outside of the record at which time the bell crank I8 is operated to lift the needle 2 of the stylus arm clear of the surface of the record. The stylus arm 2 can thereafter be returned by means of a pusher arm 2| to its starting position toward the center of the record 5.

The bell crank lever I8 is operated by the movement of the pivoted arm 20, which arm has a projection which bears against a cam 22 so that it is oscillated by the rotation of the cam (Figure 1). The pusher arm 2| is pivotally connected to the cam'22 by a lost motion connection and extends from the cam-22 to contact the stylus arm 2 as shown and to move the stylus arm toward the center of the record to the startingposition. The cam 22 is driven counter-clockwise by an electric motor 23 and an associated speed reducer. The motor 23 is controlled by various switches and circuits hereinafter to be described, so that it runs only at predetermined intervals, at the beginning and end-of the sound producing cycle. By operation of the'motor 23 the cam 22 andthe associated mechanism, the stylus arm 2 is first lifted and thereafter pushed by the pusher arm 2| to its starting position adjacent the center of the record, whereupon the bell crank lever I8 is retracted and the stylus arm 2 is lowered to allow the needle 2 to contact the surface of the record 5.. The stylus arm is moved toward the outer edge of the record by cooperationiof the needle 2':with the sound groove 6.. V .I

The supply of electrici current; to. start the motor '23 and to continue its 'operatlon'for 1a supplied to the motor through the connections 28 after the starting switch 24 has opened. The current will continue to be supplied to the motor 23 until the cam 22 has revolved for-substantially one revolution, whereupon the abutment 26 on its return stroke will open the limit switch 21. Themotor 23 will then stop and the cam 22 and its associated equipment will be in the position shown in Figure 1, but the stylus arm 2 will be at the starting position adjacent the center of the record.-

, The tone arm support table l5, the limit switch 21, thecarn 22, thebell crank lever l8, the movable arm 20 and the motor 23 are all mounted for convenience on a plate 29 shown in chain lines. The plate 29 is adjustable with respect to the turntable 8 so that when the record repeat mechanism is set up, the position of the stylus arm 2 with respect to the st-arting groove of the record 5 may be accuratelyset. The starting position of the tone arm 2'is sufficiently close so long as it falls within an area 30 of the record 5 as shown in dotted lines in Figure 2. At the start the apparatus is adjusted so that the point of the needle 2' falls in the area 30, and the revolution of. the record 5 in a clockwise direction will cause the needle to describe a truly circular path with reference, to the record and enter the widely open spiral! which leads directly to the sound track at a'definite point. The needle 2 will therefore always :come into the same exact point in the sound track at every start of the record 5 and in the same timjed relation with the operation of the remainder of the apparatus. In order to insure that the stylus arm 2 will describe a truly circular path on the record 5 until the needle contacts the starting groove 1, the stylus arm is provided with a spring 3| having a flattened portion which bears against a suitable arcuate friction pad 32 which is faced with a suitable material such as leather. The friction between the flattened end of the spring 3| and the friction pad32 is sufiicient to insure that the needle 2' will track on the record in a truly circular path. Thefrictionis not, however, suflicient to effect the movement ofthe stylus arm, under the infiuence of the sound track 6.

The timing disc .assembly.25. (see Figure 4) is made up of a number of parallel circular timing discs 33 which .are spaced apart and .fixedly mounted on a shaft 34. Theends of the shaft are carried insuppor ts 35 and by removing the bearing caps 36 the .whole assembly may be lifted from the supports. Each record has different soundeffects which require different robot movements; Therefore'it is necessary to have a timing disc assembly for use with each record.

- Connected to the shaft 34 is a worm gear 31 which is drivenby'a'worm '38fon the supporting shaft. I. To. facilitatethe changing of the (1156 assembly- 25 when required, I'prefer to make the gear 31 so that the. shaft 34 may be readily separated therefrom. Each of the disc assemblies has associated therewith a switch 39 which is in circuit with the electrical apparatus to be operated, such as the robot. Each switch will control a circuit governing a definite movement of the robot, so that a separate disc and associated switch is required for each distinct movement (for convenience We have shown in Figure 2 only one such circuit connected to the robot), such as moving the arm, turning the head, etc. One of the timing discs (for example, the extreme left disc of the assembly shown in Figure 4), has a projecting pin 40 which actuates the starting switch 24. It also has on the opposite side of the disc a projecting pin 4! which actuates a switch 42 which controls the lifting of the stylus arm 2 away from the record at the end of the playing thereof.

The switches 39, are each operated by the movement of an associated switch arm 43, the end of which is resiliently urged against the perimeter of the disc 33 to enter the notches 44 as they move past the arm, and thus controls the operation of each switch. When the end of the arm 43 enters one of the notches, a circuit is completed through that switch to the robot and will cause a desired movement of the robot. Each of the discs 33 preferably controls one movement of the robot, such as the movement of one arm. The number of discs in the timing disc assembly will, therefore, depend upon the number of types of movements which it is desired to initiate. The number of notches in each disc will depend on the number of times a certain robot movement is to be made and the location of the notches depends on when the movement is to be made, relative to the narrative.

The notches 44 are placed in each disc 33 by listening to the record 5, associated with such a disc assembly, while it is being played and as soon as a certain movement of the robot should be initiated a mark is placed on the appropriate disc with reference to the arm 43 and a notch 44 is then filed into the disc in this location.

When the sound effects (on the record have been finished, it is undesirable to have the needle 2 continue in contact with the record 5 as this makes an annoying, scraping sound through the loud speaker 4 in the robot and diminishes the eiiectiveness of the display. To ensure the lifting of the needle away from the record, the switch 42 is so placed that it will be operated immediately after the finish of the sound effects so that the switch 42 will be closed by contacting pin 4! and a current will pass from one side of the current supply line through the switch 42 and through a switch 46 to the motor 23 and from the motor to the other side of the supply line. This will cause the motor 23 to rotate counter-clockwise until the movable arm is forced to the right a short distance, sufficient to operate the bell crank lever I8 and lift the platform I5, whereupon the stylus arm will be lifted sufiiciently to raise the needle 2' clear of the record. After a short predetermined travel of the cam a projection 4'! on the movable arm 20 will open the switch 46 and cut oiT the current to the motor 23. The movement of the cam 2| during this operation is insufiicient to move the pusher arm 2| far enough to allow the limit switch 2'! to close.

The gear ratio between the turntable 8 and the timing disc assembly 25 is a multiple of unity so that thestylus can conveniently be placed at the same point in the rotation of the record at each cycle of the timing switch. The most convenient gear ratio is that in which the playing time of the record 5 is slightly less. than the time required for a complete revolution of each of they timing discs 33. This places the tones on the record in direct time relation to the cycle of the timing disc. The timing discs takes a slightly longer time to complete a cycle than the playing time of the record. This need only be a matter of seconds, enough to give sufficient time for the stylus arm 2 to be lifted before the cycle of operations is repeated by closing the starting switch 24 by contact of the projection 40 with the arm of the switch 24.

The foregoing description illustrates a particular embodiment of my invention which is capable of use in many other situations and in other embodiments. For example, the sound producing mechanism may employ the film of a sound track and associated sound reproducing equipment instead of a record and various types of apparatus such as animated displays, pictorial representations, etc., may be operated, and electrical and lighting eifects may be controlled in correlation with the sounds produced, and in permanent synchronization therewith.

It is also within contemplation of my invention to in terpose between the timing disc assembly and the robot a progressively operable selector switch, in which case the timing disc need consist of only one timing disc, arranged to advance the switch contact arm step by step at desired intervals, The timing disc assembly could also comprise a cylindrical body having appropriate depressions or projections to cause the switches associated therewith to operate.

With the construction which I have illustrated and described, it is apparent that the record may be played as many times as is desired and in perfect synchronization with the associated apparatus. The apparatus is comparatively inexpensive, simple to construct and maintain and will continue to automatically operate as long as desired and in addition it is a very simple operation to change from one sound sequence and robot movements to a different sound sequence and robot movements.

While I have described and illustrated a preferred embodiment of my invention, it is to be understood that various changes may be resorted to, without departing from the spirit of my invention or the scope of the claims.

I claim:

1. In sound synchronizing apparatus, the combination of a phonograph having a record supporting turntable, means for driving the turntable, a timing disk geared .to the turntable driving means, a stylus arm pivotally secured to traverse the record on the turntable, a table for supporting the arm, a bell crank lever for raising and lowering the table, a rotatable cam, a connection between the cam and the bell crank lever whereby the lever may be operated, a motor for turning the cam, a pusher arm extending from the cam to the stylus arm for moving the stylus arm across the record, means associated with the disk for initiating the operation of said motor, means for controlling the operation of the motor for a predetermined period of time, and frictional means between the table and the arm for restraining the movement of the arm when not in engagement with the record groove.

2. A repeating mechanism for a phonograph having a turntable, a motor for driving the turntable and a pick-up arm which is moved across the turntable during the playing of the record in one direction, which mechanism comprises a support under the pick-up arm, a mechanism for raising and lowering the support for lifting and lowering the pick-up arm, a push rod for moving the arm laterally in one direction only after the arm has been elevated, a common member for operating said mechanism and said push rod, a motor for operating said member, and means driven by the turntable for controlling said motor.

3. A display device for repeatedly producing a combined audible and visible display wherein the visible demonstration is correlated to the audible demonstration, comprising a phonograph with a turntable, a motor for driving the turntable, a record on the turntable, a pick-up arm cooperating with the record and movable during the playing of the record from an initial position to an end position, a robot having movable pants and circuits through which the movement of the parts is con-trolled, a circuit-closer driven synchronously with the turntable, electrically operated means for lowering the pick-up arm onto the record to initiate the playing of the record and for lifting the tone arm and returning it to starting position after the record has been played, said circuit-closing means also controlling said last-named electrically operated means, and means controlled by the circuit-closer for controlling the circuits which operate the robot parts whereby the movement of the parts of the robot are always in predetermined relation to the playing of the record.

FRED C. WALLACE. 

